Drum type magnetic separator



Nov. 26, 1957 B. A. PALM DRUM TYPE MAGNETIC SEPARATOR 2 Sheets-Sheet 1 Filed Feb. 17, 1954 m m w m Nov. 26, 1957 B. A. PALM 2,814,386 DRUM TYPE MAGNETIC SEPARATOR Filed Feb. 17, 1954 v 2 Sheets-Sheet 2 IN V EN TOR.

03am -BY g y United States Patent Office 2,8l43dfi Patented Nov; 26, 1957 DRUM TYPE MAGNETIC SEPARATOR Bernhard A. Palm, Milwaukee, Wis., assignor to Diugs Magnetic Separator Co., Milwaukee, Win, a corporation of Wisconsin Application February 17, 1954, Serial No. 410,869

7 Claims. (Cl. 209--223) The present invention relates generally to improvements in the art of refining slurry containing fine magnetic particles mixed with impurities, and relates more specifically to improvement in the construction and operation of drum type magnetic separators especially adapted to remove concentrates from tailings constituting magnetite ore pulp or the like.

The primary object of my invention is to provide an improved drum type magnetic separator which is simple in construction and highly eflicient in operation.

It has heretofore been proposed to treat slurry having fine magnetic particles suspended in liquid, with the aid of separating units each comprising a rotary horizontal drum provided with internal magnets and having its lower peripheral portion revolvable through a basin of the slurry, and wherein the slurry was admitted upwardly toward the drum periphery at the medial portion of the basin while the washing liquid containing the tailings was removed from one end of the basin and the concentrates were discharged from the field of magnetic influence and from the drum at the opposite basin end. This type of machine is also known as a counter flow wet separator and is especially useful for the treatment of magnetite ore pulp, and since the fine ore particles are intimately intermingled with gangue and slimes it is necessary to provide most effective flow of the slurry and presentation of the constituents thereof to the magnetic field and to the washing water in order to insure eflicient, reliable and automatic functioning of the separators during commercial use. None of the prior separating units of this type have been entirely satisfactory because they failed to properly conduct the fluent mixtures through the treating zones so as to insure the production of sufliciently clean final concentrates when handling variable quantities of the ore pulp, and also because they were relatively complicated and difficult to adjust in order to provide suflicient commercial capacity.

It is therefore a more specific important object of the present invention to provide an improved counter flow wet magnetic separator, wherein the slurry is most effectively presented to the separating zone and in which the magnetic particles are thoroughly washed so as to insure rapid and continuous production of relatively clean concentrates.

Another important object of this invention is to provide an improved drum type magnetic separating unit of relatively small size and of simplified structure but having enormous capacity and being adapted to accommodate itself to varying feed conditions.

A further important object of the invention is to provide magnetic drum type separating machine which is especially adapted to separate fine magnetite particles from ore pulp and Which is capable of functioning automatically and with minimum attention to treat varying quantities of the pulp having variable consistency.

Still another important object of my invention is to provide an improved magnetic separating device which may be efiectively operated in series with other similar devices to produce clean final product when operating on even the most tenacious and relatively inseparable mixtures.

An additional important object of this invention is to provide an improved drum type magnetic separating installation comprising relatively few parts which may be readily fabricated and assembled and operated at moderate cost to treat various kinds of slurry containing fine magnetic particles.

These and other more specific objects and advantages of the invention will be apparent from the following detailed description from which it should be noted that the gist of the invention is the provision of a magnetic separating unit comprising a pulp confining basin having a tailings overflow at one end and a concentrates discharge at its opposite end, a drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in the basin from the overflow toward the discharge end thereof, magnets within the drum for creating a magnetic field along the immersed peripheral portion of the drum, and conduits and passages for most effectively feeding the fresh slurry to the drum through the mid-portion of the basin and for delivering the tailings to the overflow and the concentrates to the discharge in clean condition.

A clear conception of the features constituting the present improvement, and of the construction and operation of a pair of magnetic separating units embodying the invention, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a somewhat diagrammatic vertical section through a pair of similar drum type magnetic separators operable in series, the section having been taken along the line 1-1 of Fig. 3;

Fig. 2 is a similarly diagrammatic transverse vertical section through the duplex separating installation of Fig. l, the section being taken along the irregular line 22; and

Fig. 3 is a top view of the same installation.

While'the invention has been illustrated and described herein as'having been embodied in a dual drum type separating installation especially adapted to handle magnetite ore pulp or slurry, it is not my desire or intent to unnecessarily restrict the same by virtue of this specific embodiment; and it is also contemplated that descriptive terms employed herein be given the broadest interpretation consistent with the disclosure.

Referring to the drawings, the dual separating installation shown by way of illustration embodies an upper separator A and a lower separator B, both mounted upon a common frame 5, and each comprising a separating chamber or liquid basin 6 having a tailings or gangue overflow weir 7 at one end and a concentrates discharge chute 8 at its opposite end; a pair of hollow drums 9 each rotatable about a normally stationary horizontal shaft 10 and having its lower peripheral portion 11 immersed within and revolvable in the direction of the arrow within the fluent pulp of the adjacent basin 6; a bank of electromagnets 12 mounted upon each shaft 10 within the corresponding hollow drum 9 for creating a magnetic field along the adjacent peripheral drum portion 11; a pulp supply hopper 13 communicating through a duct 14 with a pulp inlet conduit 15 which diverges and is directed tangentially relative to the adjacent drum portion 11 of each unit between the weir 7 and chute 8 thereof; a series of tubular members 16 forming segregated passages extending transversely through the pulp inlet conduit 15 from the bottom of each basin 6 to the overflow weir 7 thereof; and a chain drive 17 for constantly revolving the drums 9 about their respective supporting shafts 10.

The main frame may be constructed of sturdy sheet metal and structural steel so as to properly support the two separating units A and B for cooperation in series whereby the product delivered from the upper separator A may be further treated in the lower separator B, and the conduits 19 which conduct the concentrates from the upper to the lower unit may be provided with demagnetizing coils 20 as shown in Fig. 1. Each of the basins 6 has a U-shaped bottom, one wall 21 of which is inclined upwardly toward the tailings overflow weir 7, while its other wall 22 is inclined upwardly toward the concentrates discharge chute 8. The basin bottom wall 21 is adapted to direct the tailings laden liquid with considerable velocity from the bottom of the separating chamber through the tubular members 16 toward the weir 7, and the other wall 22 has an arcuate upper portion 23 which cooperates with the adjacent magnets 12 and drum periphery to provide a final washing and pick-up zone 24 in advance of the concentrates discharge chute 8. Located below each of the inclined basin walls 22 is a relatively long fresh water supply chamber 25 having a supply pipe 26 at its lower portion and an outlet opening 27 at its upper end above the level of the liquid in the adjacent basin 6 for delivering an abundant supply of washing liquid to the upper end of the pick-up zone 24 throughout its entire width.

The pulp supply hopper 13 of the upper separating unit A should communicate with a source of abundant fresh slurry under considerable hydrostatic head and containing a mixture of fine magnetic particles, tailings and water, and may be provided with a distributing bafile plate 29 as illustrated in Figs. 1 and 3; and the bottom of each hopper 13 has a series of fresh water supply pipes 30 communicating therewith and directed through the adjacent duct 14 which extends laterally throughout a considerable portion of the basin width, as shown in Fig. 2. Each of the upwardly inclined diverging inlet conduits 15 is of approximately the same lateral width as that of the adjacent duct 14, and may be provided at its upper end with short flanges 31 extending along the adjacent drum periphery, and a dam 32 may also be provided at each end of each drum 9 near the fresh water outlet opening 27 in order to permit some of the washing liquid from the chamber 25 to fiow into the medial portion of the basin 6. The periphery of each drum 9 above the discharge chute 8 thereof, should also be provided with a fresh water spray pipe 33 for washing adhering particles of magnetic material from the drum periphery beyond the field of magnetic influence and the tailings discharge weir 7 should be approximately the same width as the length of the drums 9.

- Each of the hollow drums 9 is formed of durable nonmagnetic metal and has a pair of opposite end heads 35 provlded with central hubs which are journalled for rotation upon the adjacent normally fixed shaft 10, and one of these end heads 35 of each drum assemblage has an annular extension 36 provided with a sprocket constituting part of the chain drive 17 as depicted in Figs. 1, 2 and 3. The main frame 5 is provided with a bracket 37 spanning the lower separator B as shown in Figs. 1 and 3, and a suitable electric motor and speed reducer, not shown, may be mounted upon this. bracket 37 in an obvious manner, in order to propel the chain drive 17 and to thereby rotate the drums 9 at any desired speed, in the directions indicated by the arrows in Fig. l. The banks of magnets 12 for creating the magnetic fields along the drum peripheries 11 are also of well-known construction, and are rigidly attached to the adjacent shafts 10 which are adapted to be clamped in split bearings 38 carried by the main frame 5 but are rotatably adjustable so as to vary the positions of the magnets relative to the adjacent basins 6. The magnets 12 are sealed within the drums 9 and may be energized by conductors extending from switch boxes 40 through central openings 39 in their supporting shafts 10, and this adjustment of the magnets may be effected from the exteriors of the drums 9 while the separators are operating.

The tailings and gangue fiowing over the weirs 7 may be discharged from each separating unit along a trough 42 having oppositely inclined bottom plates directed toward chutes 43 at the opposite sides of the unit, and as previously stated the concentrates delivered from the upper separator A flow toward and drop by gravity through the conduits 19, while the final concentrates delivered from the lower separator B drop by gravity upon a discharge chute 44 at the delivery end of the frame 5. The demagnetizing coils 20 which surround the conduits 19 serve to demagnetize the concentrates dropping toward the lower separator B, but the use of these coils is optional, and the conduits 19 may also be provided with a barrier wall 45 for preventing escape of spray liquid and concentrates delivered over the chute 8. The chain drive 17 may also be provided with a guard 46 as shown in Fig. 2, and any desired number of the separators A and B may be caused to operate either singly or in series.

While the normal operation of the improved separators should be apparent from the foregoing description of the construction and disposition of parts, a short rsum will be given. When the dual separator is functioning, the drums 9 should be constantly rotated at the desired speed, the electro-magnets 12 should be energized to create a desirably strong field of magnetic influence along the advancing lower drum portions 11, and an abundant supply of slurry should be admitted to the upper hopper 13 while a likewise abundant supply of fresh water should be injected through the pipes 30, 33 and chambers 25. The pulp will then flow through the passages 14 and will be mixed with and agitated by the jets of fresh water delivered through the pipes 30 and the mixture will be presented at decelerating velocity through the expanding ducts 15 to the travelling lower drum portions 11 and the magnetic flux field created by the magnets 12. These lower drum portions quickly accumulate magnetic particles thereon and the magnets 12 successive individual poles of which preferably have opposite polarity, function to roll the adhering particles upon the outer surfaces of the drum portion 11 thereby permitting the liquid in the basin to quickly and thoroughly wash out the tailings and slime.

As the adhering magnetic particles enter the pick-up zones 24 they are further subjected to fresh water entering these zones from the chambers 25 through the openings 27, thus further subjecting the magnetic particles or concentrates to thorough washing and rinsing, and any particles which drop from the advancing drum portions 11 within the pick-up zone are quickly returned by magnetic influence to the adjacent drum surfaces. When the adhering magnetic concentrates are elevated out of the liquid and beyond the zone of action of the magnets 12, most of them drop from the adjacent drums onto the chutes 8 and any of these particles which tend to stick to the rising drum surfaces are washed into the chutes 8 by the sprays delivered from the pipes 33. The separated tailings, gangue and slimes are washed from the basins 6 by the flow of excess liquid downwardly and upwardly along the basin walls 22, 21 and through the tubular passage members 16 toward the tailings overflow weirs 7, and are ultimately delivered to the chutes 43 over the plates 42. The concentrates delivered from the upper separator A are further and finally treated in like manner in the lower separator B, thus insuring thorough and automatic separation of the magnetic concentrates from the non-magnetic impurities.

From the foregoing detailed description of the construction and operation of the improved drum type magnetic separators, it should be apparent that the present invention provides a simple and compact unit of relatively large capacity adapted to remove clean magnetic particles from slurry in a most efficient manner. The slurry or pulp is efliectively presented to the advancing lower drum portions 11 within the fields of magnetic influence gradually and throughout extensive areas, and the magnetic particles which adhere to the drums 9 are gradually but thoroughly washed and rinsed by the abundance of well distributed fresh water admitted to the basins 6 over the dams 32 and through the pick-up zones 24 from the elongated supply chambers 25. The fresh liquid admitted from the pipes 30 should be injected at considerable velocity in order to effect the initial agitation of the pulp, and the sprays delivered from the pipes 33 should also be projected against the adjacent drum surfaces with considerable velocity so as to thoroughly cleanse these surfaces.

The improved separators A and B may be utilized either singly or in multiple series, and by mounting both of these separators upon a common frame they may be effectively driven from a common source of power and may also be shipped and installed as a unit. The U- shaped formation of the basin walls 21, 22 serves to most eflectively deliver the tailings upwardly through the tubular conducting members 16 toward the weir 7 and for preventing undesirable accumulation of tailing within the separating chamber, but the lower portion of the basin 6 may be provided with a drain and clean-out opening which should be sealed during normal operation. The elongated fresh water supply chamber 25 should also be of considerable length in order to insure most eflective distribution of the wash water, and the inclined plate 29 in the upper hopper 13 also produces eflective distribution of the entering pulp. The position of the normally fixed magnets 12 may also be adjusted at any time in order to insure most eflicient location of the magnetic field, and the flow of fresh water through the pipes 30, 33 may also be regulated during normal operation of the separators. The improved separators may be constructed in various sizes for diverse uses, and are especially useful for separating fine magnetite ore particles from tailings in the mining industry.

It should be understood that it is not desired to limit this invention to the exact detail-s of construction and operation of the magnetic separators herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. In a magnetite ore pulp separator, means forming a pulp confining basin having a tailings overflow at one end and a concentrates discharge at its opposite end, a hollow drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in said basin from said overflow toward said discharge end, means within said drum for creating a magnetic field along said immersed peripheral drum portion, means forming a diverging pulp inlet conduit of gradually increasing cross-section directed tangentially relative to said lower drum portion between said basin ends and toward said concentrates discharge, and means forming a segregated passage extending through said diverging conduit and connecting said basin with said tailings overflow.

2. In a magnetite ore pulp separator, means forming a pulp confining basin having a tailings overflow at one end and a concentrates discharge at its opposite end, a hollow drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in said basin from said overflow toward said discharge end, means Within said drum for creating a magnetic field along said immersed peripheral drum portion, means forming a diverging pulp inlet conduit of gradually increasing cross-section directed tangentially relative to said lower drum portion between said basin ends and toward said concentrates discharge, and means forming passages segregated from and extending transversely through said pulp inlet means and toward said tailings overflow and connecting the lower portion of said basin with said tailings overflow.

3. In a magnetite ore pulp separator, means forming a pulp confining basin having a tailings overflow at one end and a concentrates discharge at its opposite end, a hollow drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in said basin from said overflow toward said discharge end, means within said drum for creating a magnetic field along said immersed peripheral drum portion, and means forming a gradually expanding pulp inlet conduit directed through the medial portion of said basin tangentially relative to said peripheral drum portion and toward said concentrates discharge and also forming passages segregated from and extending transversely through said inlet conduit and connecting the bottom of said basin with said tailings overflow.

4. In a magnetite ore pulp separator, means forming a pulp confining basin having a U-shaped bottom provided with walls diverging upwardly toward a tailings overflow at one end and a concentrates discharge at its opposite end, a hollow drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in said basin from said overflow toward said discharge end, means within said drum for creating a magnetic field along said immersed peripheral drum portion, means forming a diverging pulp inlet conduit of gradually increasing cross-section directed from one of said basin walls tangentially relative to said lower drum portion between said basin ends and toward said concentrates discharge, and means forming a segregated passage extending through said conduit and connecting said basin with said tailings overflow.

5. In a magnetite ore pulp separator, means forming a pulp confining basin having a U-shaped bottom bounded by walls diverging upwardly toward a tailings overflow at one end and a concentrates discharge at its opposite end, a hollow drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in said basin from said overflow toward said discharge end, means within said drum for creating a magnetic field along said immersed peripheral drum portion, means forming a diverging pulp inlet conduit of gradually increasing cross-section directed from said basin wall nearest said overflow tangentially relative to said lower drum portion between said basin ends and toward said concentrates discharge, and means forming segregated passages extending transversely through said pulp inlet conduit and toward said tailings overflow parallel to the adjacent basin wall, said passages conecting the bottom of said basin with said tailings overflow.

6. In a magnetite ore pulp separator, means forming a pulp confining basin having a tailings overflow at one end and a concentrates discharge at its opposite end, a hollow drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in said basin from said overflow toward said discharge end, means within said drum for creating a magnetic field along said immersed peripheral drum portion, a casing forming a diverging pulp inlet conduit of gradually increasing cross-section directed tangentially relative to said lower drum portion between said basin ends and toward said concentrates discharge, a series of tubular members forming segregated parallel passages extending transversely through said pulp inlet casing and upwardly toward said tailings overflow and providing communication between the latter and said basin, and means for admitting an abundance of fresh liquid to said basin beneath said concentrates discharge and above the level of the liquid in said basin.

7. In a magnetite ore pulp separator, means forming a pulp confining basin having a tailings overflow at one end and a concentrates discharge at its opposite end, a hollow drum rotatable about a horizontal axis and having its lower peripheral portion immersed within and revolvable through the pulp in said basin from said overflow toward said concentrates discharge end, a series of magnets within said drum for creating a magnetic field along said immersed peripheral drum portion, a casing forming a diverging pulp inlet conduit of gradually increasing crosssection throughout its entire length directed through the medial portion of said basin tangentially relative to said peripheral drum portion and toward said concentrates discharge and also forming passages segregated from and extending transversely through said conduit and directed upwardly at an oblique angle to conect the basin with said tailings overflow, and means forming spaced pick-up zones for magnetic particles within said basin beyond said inlet conduit and in advance of said concentrates discharge.

References Cited in the file of this patent UNITED STATES PATENTS 2,160,628 Steffenson May 30, 1939 2,695,709 Stearns a- Nov. 30, 1954 FOREIGN PATENTS 24,872 Norway Aug, 3, 1914 

